The Sangha has been interpreted as a community of Buddhist monks and nuns. But in the words, "I, with all the Sangha," the term dictates the idea of believers in a broader sense. The Sanskrit word sangha means "an intimate and faithful group of many believers."
Shakyamuni Buddha named Sangha to the community of fellow believers who sought the same teachings as his disciples.
People find practicing the Dharma, the Buddha’s teachings, in complete isolation difficult. Most of us are apt to become lazy and lose the Path. But we can steadily advance by sharing the teachings, helping each other with our awareness, and encouraging one another. This is why the Buddha regarded the Sangha as one of our mental foundations.